Sis-ht in Saz'aoes. i8i 



V5 



mistake which eye specialists and writers ou the 

 eye make is that they think too much about tlie 

 eye. When they affirm that the conditions of our 

 civilization are highly injurious to the sight, do 

 they mean all the million conditions, or sets of 

 conditions, embraced by our system, with the 

 infinite variety of occupations and modes of living 

 which men have, from the lighthouse-keeper to the 

 worker underground, whose day is the dim glimmer 

 of a miner's lamp ? " An organ exercised beyond 

 its wont will grow, and thus meet increase of 

 demand by increase of supply," Herbert Spencer 

 says ; but, he adds, there is a limit soon reached, 

 beyond which it is impossible to go. This increase 

 of demand with us is everywhere — now on this 

 organ and now ou that, according to our work and 

 way of life, and the eye is in no worse case than 

 the other organs. There are among us many cases 

 of heart complaint ; civilization, in such cases, has 

 put too great a strain on that organ, and it has 

 reached the limit beyond which it cannot go. And 

 so with the eye. The total number of the defective 

 among us is no doubt very large, for we know that 

 our system of life retards — it cannot effectually 

 prevent — the healthy action of natural selection. 

 Nature pulls one way and we pull the other, com- 

 passionately trying to save the unfit from the 

 consequences of their unfitness. The humane in- 

 stinct compels us ; but the cruel instinct of the 

 savage is less painful to contemplate than that 

 mistaken or perverted compassion which seeks to 



